Overview of Investigation to Understand Progression of

Concrete Tie Conditions in High Speed Applications

Jeff HendersonProject Engineer

Prepared for theInternational Concrete Crosstie and Fastening System Symposium

June 2012

Project Team

o FRA Office of Research and Development

o AMTRAKo ENSCO

FRAOR&D

Funded under BAA-2010-1 Sponsored by the Federal Railroad Administration

Research Objectives

• Develop a better understanding of the progression of defects in concrete ties over time

• Advance the use of machine vision technology in concrete tie inspection

• Improve concrete tie inspection practices for high-speed applications

Focus of Study

Determine progression rate of cracks in concrete crossties

Enlargement

• Consider a statistically significant sample size (~250,000 ties)

• Employ three measurement surveys spanning 1.5 years

Motivation for Study

Hairline cracks ultimately result in tie failures upon reaching the rail seat

Intended Broader Impact• More efficient inspection

intervals• Improved maintenance

planning and budgeting• Improved safety and net

operating efficiency

Main Technical Objective

Better understand the progression from “A” to “B”

BA

Hairline End Crack Tie Failure

High-level Approach• Assess progression of tie condition at discrete states• Combine results to paint a more continuous picture

Early Mid Late

Methodology• Crack progression assessed

“virtually” rather than “live”• Machine vision will be used to

help locate cracks• Crack measurements will be

made manually

Test Equipment• Track Bed Imaging System• Rail Side View Imaging System

Track Bed Imaging

Rail Side View Imaging

Implementation Plan Overview

Test Zone 1

High Street to Atwells• Start/End MP: 143 – 184

• Tie Installation Dateso Brand newo 1978-1979 San-Velo 1993-1994 Rocla

• Traffic: Passenger & Freighto Passenger tonnage: 4.7 to 4.9 MGT o Freight tonnage: 0.1 to 1.5 MGT

• Track Miles: 82 miles

Test Zone 2

Hebronville to Mansfield• Start/End MP: 193 – 204

• Tie Installation Date: 1979 San-Vel

• Traffic: Passenger & Freighto Passenger tonnage: 4.7 to 4.9 MGT o Freight tonnage: 0.6 to 0.8 MGT

• Track Miles: 22 miles

Technical Challenges

• Challenge 1: Locating hairline cracks in a set of ~250,000 concrete ties

Challenge 2: Precisely aligning ties between consecutive runs

“Enlarge the needle” “Get your ducks ties in a row”

Main objective of project: To better understand the progression of cracks in concrete ties

Final report to discuss:– Improved concrete tie inspection practices and intervals– Approaches for improving the reliability of concrete tie

inspections– Approaches for improving tie inspection efficiency– Approaches for reducing concrete tie inspection cost

Summary

AcknowledgementsFRA Office of Research and Development:

• Mr. Hugh Thompson, FRA COTR

Amtrak

• Mr. Joe Smak

• Mr. Michael Trosino

• Mr. Steven Sawadisavi

Thank you